Magnetic random access memory (MRAM) is a non-volatile random access memory which gains popularity in recent years as potential replacement for dynamic random access memory (DRAM), static random access memory (SRAM) and flash. MRAM, for example, includes magnetic tunnel junction (MTJ) element which uses magnetic polarization to store information. MRAM device, for example, includes MTJ stack layers having a plurality of magnetic layers. The MTJ stack layers are generally connected to interconnects in the interlevel dielectric (ILD) layer. The various MTJ stack layers, however, are not transparent to light. Thus, when the various MTJ stack layers are patterned using lithography and etch techniques, the patterned MTJ stack layers may not be aligned to the underlying interconnect structures due to non-transparent metal layers of the MTJ stack and thus fail to couple to the underlying interconnect structures. This may render the MRAM device inoperable.
Accordingly, it is desirable to provide reliable and cost effective techniques to properly align the various MTJ stack layers with underlying interconnect structure to ensure electrical connection for the MRAM device.